Method for manufacture of information handling system laminated housings

ABSTRACT

An information handling system housing is manufactured from a laminate material having a stainless steel exterior and magnesium interior that are encapsulated with injection molding. A thin sheet of stainless steel is formed to have a lip that meets against the magnesium and is secured in place with injection molding material. In one embodiment, an injection molding tool holds the laminate material in place to encapsulate the perimeter of the material with injection molding material and also activates an adhesive that holds the laminate material together, such as by applying pressure and heat to the laminate material.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to the field of informationhandling system portable housings, and more particularly to a system andmethod for manufacture of information handling system laminatedhousings.

2. Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Portable information handling systems present an attractive option tomany end users. A portable information handling system generallyincludes integrated I/O devices and an integrated power source so thatthe system operates without physical wire connections, such as a powercable to an external power source or peripheral cables to external I/Odevices. For example, one common configuration used in portableinformation handling system housings is a clamshell configuration inwhich a lid rotationally couples to a chassis, the lid integrating adisplay that closes over top of a keyboard disposed in the chassis. Thechassis contains a rechargeable battery that powers processingcomponents disposed within the chassis. During portable operations, anend user rotates the lid to an open position to expose the display andkeyboard and runs the processing components on power provided from thebattery. When not operating, the system closes into a compact footprinteasily transported by an end user.

Design and manufacture of portable information handling system housingspresent a number of challenges. One concern is providing a housing thathas adequate strength with minimal weight. Another concern is providinga housing that prevents excessive heat transfer from internal componentsto the housing outer surface such that the surface is not comfortable toan end user's touch. Another concern is providing shielding fromelectromagnetic interference (EMI) generated by components within thehousing. In addition to such practical concerns, end users also desirehousings that have an attractive and durable appearance. One materialoption for a portable housing is stainless steel because it is a robustmaterial with good strength and hardness. Although stainless steelprovides an aesthetically pleasing and durable housing with good EMIshielding, the material is somewhat heavier than other options and thustends to result in housings that are less portable. Another materialoption is die cast magnesium housing portions. Magnesium housings weighless than similar-sized steel housings and have relatively goodstiffness, however, the cast magnesium has a rough appearance thattypically needs mechanical touch-up and paint in order to haveaesthetically acceptable appearance. Non-metal materials are availablethat have reduced weight relative to metal materials, however, non-metalmaterials tend to be less robust than metal materials and tend to needmetal shielding to contain EMI. As processing components have becomemore compact and powerful, manufacturers have attempted to reduceportable housing size and thickness, such as by using thinner materials.Currently-used materials do not offer much in the way of additional sizereduction to minimize weight without sacrificing the robustness of thehousing.

SUMMARY OF THE INVENTION

Therefore a need has arisen for a system and method which provide aportable information handling system housing that is adequately robust,stiff and hard to provide an aesthetically-pleasing durable enclosure.

In accordance with the present invention, a system and method areprovided which substantially reduce the disadvantages and problemsassociated with previous methods and systems for manufacture of aninformation handling system housing. Plural materials form a laminatematerial having at least a portion of its perimeter encapsulated withinjection molding. In one embodiment, manufacture of the housing isperformed by near simultaneous activation of laminate adhesive andinjection molding. The adhesive is activated while the laminatematerials are disposed within an injection molding tool so that thelamination and injection molding are supported by one iteration ofclosing the injection molding tool.

More specifically, an information handling system is built by laminationof inner and outer materials with the inner material providing lowweight structural support, such as with magnesium, and the outermaterial providing stiffness and an aesthetically-pleasing appearance,such as with a thin sheet of stainless steel. The outer material isformed with a lip along its perimeter that meets against the innermaterial and contains an intermediate filler material, such as paper orfiberboard or plastic. A high shear adhesive applied to the intermediatefiller material glues the inner and outer materials to the fillermaterial to form a laminate material. The perimeter of the laminatematerial has injection molding material, such as thermoplastic, formedaround at least a portion of the lip to encapsulate the laminatematerial where the outer edge of the outer material would otherwise beexposed. Encapsulation of the outer perimeter of the laminate materialhelps to maintain the structural integrity of the material and preventsend user contact with the edge of the material used to create thelaminate. In one embodiment, activation of adhesive in the laminate isperformed during the injection molding process, such as by heating orcompressing the laminate materials with an activation temperature orpressure when the laminate materials are disposed in an injectionmolding tool. Insert injection molding is performed with one iterationof the injection molding tool from insertion of the laminate materialswith the injection molding tool open, activation of the adhesive andinsertion injection molding with the injection molding tool closed, andrelease of a completed housing portion when the injection molding toolopens.

The present invention provides a number of important technicaladvantages. One example of an important technical advantage is that aportable information handling system has a hard stainless steel outermaterial layer that has a durable and scratch resistant surface and alight weight inner material layer that provides improved stiffness witha less thick and heavy construction. Injection molding of an outerperimeter provides aesthetically-pleasing molded details while providingadditional security by integrating the stainless steel outer materiallayer with inner material layers. An inner material layer of die castmagnesium provides stiffness and shielding with minimal weight whilebeing hidden from view by the outer stainless steel layer and injectionmolding finish. The extra expense of mechanically treating and paintinga die cast magnesium exterior is avoided. Adhesion of the materiallayers of the housing is accomplished in the same step as injectionmolding by providing heat, pressure and other factors as needed to thematerial while the material is held in place for the injection moldingprocess. Manufacturing time and complexity for a composite housing ofmultiple material layers are minimized, reducing assembly time, toolingcosts and total part costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood, and its numerousobjects, features and advantages made apparent to those skilled in theart by referencing the accompanying drawings. The use of the samereference number throughout the several figures designates a like orsimilar element.

FIG. 1 depicts a blown-up view of a portable information handlingsystem;

FIG. 2 depicts a blown-up view of a portion of a portable informationhandling system housing made from an encapsulated laminated material;

FIG. 3 depicts a side cutaway view of a portion of housing 12 having anencapsulated laminated material;

FIG. 4 depicts an upper perspective view of an interior portion of ahousing having features formed within the housing;

FIG. 5 depicts a side cutaway view of laminate materials disposed in aninjection molding tool for performing an encapsulation and laminationcombined process;

FIG. 6 depicts a side cutaway view of an injection molding tool havingan integrated activation device positioned to activate adhesive betweenthe laminate materials; and

FIG. 7 depicts a side cutaway view of the injection molding tool havingthe integrated activation device withdrawn from the laminate materialsto allow compression for insert injection molding.

DETAILED DESCRIPTION

An information handling system housing built from an encapsulatedlaminated material provides a sturdy structure with reduced size andweight. For purposes of this disclosure, an information handling systemmay include any instrumentality or aggregate of instrumentalitiesoperable to compute, classify, process, transmit, receive, retrieve,originate, switch, store, display, manifest, detect, record, reproduce,handle, or utilize any form of information, intelligence, or data forbusiness, scientific, control, or other purposes. For example, aninformation handling system may be a personal computer, a networkstorage device, or any other suitable device and may vary in size,shape, performance, functionality, and price. The information handlingsystem may include random access memory (RAM), one or more processingresources such as a central processing unit (CPU) or hardware orsoftware control logic, ROM, and/or other types of nonvolatile memory.Additional components of the information handling system may include oneor more disk drives, one or more network ports for communicating withexternal devices as well as various input and output (I/O) devices, suchas a keyboard, a mouse, and a video display. The information handlingsystem may also include one or more buses operable to transmitcommunications between the various hardware components.

Referring now to FIG. 1, a blown-up view depicts a portable informationhandling system 10. Information handling system 10 has plural componentsdisposed in a housing 12 that cooperate to process information, such asa CPU 14, RAM 16, a chipset 18 and a hard disk drive 20. The componentscommunicate through a motherboard 22 supported within a chassis 24portion of housing 12. A display 26 integrates in a lid 28 portion ofhousing 12 to present information processed by the components disposedin chassis 24. A keyboard 30 assembles over the top of motherboard 22 toaccept end user inputs and cover the processing components within theinterior of chassis 24. During normal operations, lid 28 rotatesrelative to chassis 24 to an open position to expose keyboard 30 anddisplay 26. When powered down, lid 28 rotates relative to chassis 24 toa closed position with display 26 proximate to keyboard 30 so that thesystem is easily transported or stored. The assembly of display 26 inlid 28 and of keyboard 30 over chassis 24 generally ensures thatinterior portions of chassis 24 and lid 28 are hidden from end user viewafter assembly of a portable information handling system within ahousing 12. Exterior portions of lid 28 and chassis 24 are visible inopen and closed positions, and face the risk of damage from impacts madeat housing 12.

Referring now to FIG. 2, a blown-up view depicts a portion of a portableinformation handling system housing 12 made from an encapsulatedlaminated material. A piece of sheet metal magnesium material 32 isformed to a shape desired for the interior of the housing. In order tominimize housing weight, magnesium material 32 has openings 34 formed init, with the opening sizes adjusted to provide a desired overall weightand strength based upon the thickness of the magnesium and the weightand strength of other materials used in the laminate. A sheet ofstainless steel material 36 is formed to a shape desired for theexterior surface of the housing. For example, stainless steel 36 isformed as a shallow drawn pan to have a lip along a portion of its outerperimeter. A filler material 38 is disposed between magnesium 32 andstainless steel 36. For example, filler material 38 is plastic,honeycomb material, perforated material, paper, or fiberboard having aspecific gravity of 0.8. Filler material 38 is exposed at openings 34 ofmagnesium 32. An injection molded perimeter material 40 surrounds andencapsulates the perimeter of magnesium 32 and stainless steel 36. Forexample, plastic material is insert injection molded around theperimeter of magnesium 32 and stainless steel 36 after the materials arelaminated together by an adhesive. Injection molded perimeter material40 captures the edges of magnesium 32 and stainless steel 36 to maintainthe laminated materials as a solid piece and to protect end users fromsharp edges that might occur around the perimeter of the laminatedmaterials. The encapsulated laminated housing material provides 70%greater stiffness than a magnesium housing, provides good shielding fromEMI emissions and provides reduced thermal transfer relative tometal-only housing materials.

Referring now to FIG. 3, a side cutaway view depicts a portion ofhousing 12 having an encapsulated laminated material. At an interiorportion 42, magnesium 32 has a desired shape for housing 12. Interiorportion 42 is generally hidden from view after assembly of aninformation handling system in housing 12. At an exterior portion 44,stainless steel 36 is disposed to present an aesthetically pleasingouter surface of housing 12. Stainless steel 36 has a lip 46 formed atits outer perimeter so that stainless steel 36 and magnesium 32 aredisposed proximate to each other along the perimeter and so that fillermaterial 38 has room between stainless steel 36 and magnesium 32 withinthe housing. For example, stainless steel 36 has a thickness ofapproximately 0.1 mm, magnesium 32 has a thickness of approximately 0.5mm, and filler material 38 has a thickness of 0.5 mm. Injection moldedmaterial 40 encapsulates the intersection of magnesium 32 and stainlesssteel 36, including lip 46, to capture the laminate materials in placeand to protect end users from potentially sharp edges, such as mightexist at the out perimeter of lip 46 where a relatively thin edge ofstainless steel would otherwise be exposed. A high sheer adhesive 48disposed on each side of filler material 38 glues stainless steel 36 andmagnesium 32 to filler material 38 to form a laminate material.

Referring now to FIG. 4, an upper perspective view of an interiorportion of housing 12 depicts features formed within housing 12. At theinterior of housing 12, magnesium 32 is exposed with openings 34 thatexpose filler material 38 disposed within the laminate material.Injection molding material 40, such as insert injection moldedthermoplastic, encapsulates the perimeter of housing 12 to capture theedge of magnesium 32 and other laminated materials exposed along theperimeter of housing 12. In addition, insert injection molding buildsfeatures within housing 12 by bonding material to filler 38 exposed atopenings 34 of magnesium 32. For example, a rib feature 50 is injectionmolded at the same time as perimeter 40. Rib feature 50 provides supportfor components disposed within housing 12, such as a display or harddisk drive. Another example of a feature included during injectionmolding is a snap feature 52 formed in an opening of magnesium 32, suchas a snap feature to accept an external cable at a port of an assembledinformation handling system. Snap feature 52 integrates with injectionmolding perimeter 40 to provide bonding around the opening of magnesium32 without the presence of filler material 38. Other types of featuresadded to housing 12 during injection molding include snap features,undercuts, connector openings and mounting features. Thus, in additionto reducing overall housing weight, openings 34 formed in magnesium 32provide improved bonding within the interior of housing 12 by exposingfiller material 38, which has better injection molding bonding qualitiesthan magnesium 32.

Referring now to FIG. 5, a side cutaway view depicts laminate materialsdisposed in an injection molding tool 54 for performing an encapsulationand lamination combined process. The laminate materials depicted by FIG.5 include stainless steel 36, filler material 38 and magnesium 32 thatare laminated together by a high sheer adhesive 48. In alternativeembodiments, alternative materials may be used form the laminate, suchas aluminum, steel or other metals conventionally used in informationhandling system housings. Injection molding tool 54 is configured tocombine an injection molding process and lamination process in a singletool closing iteration. An upper injection molding tool portion 56closes relative to a lower injection molding tool portion 58 in aconventional manner to define an area around the compressed laminatematerials that will accept injection molding material. However, becauseinjection molding compression exceeds the pressure typically used forcompressing laminate materials during activation of adhesive 48, aseparate laminate pressure activation device 60 provides compression tothe laminate materials during the lamination process that has a lowerpressure relative to the pressure applied by the injection molding tool54. In addition to applying lamination pressure, activation device 60includes a heater 62 that provides heat to the laminate materials at atemperature associated with activation of adhesive 48. For example,heater 62 provides heat at a temperature in excess of that typicallyused during injection molding, but isolates the heat to the laminatematerials for activation of adhesive 48 without interfering with theinjection molding process. In one embodiment, activation device 60 isspring-loaded so that injection molding pressure at the perimeter of thelaminate material is approximately 500 tons while adhesive activationpressure applied with spring-loading is approximately 150 PSI. Springloading allows both adhesive activation and injection molding with asingle closing movement of the tool. Further, providing heat through thespring-loaded device achieves an adhesion temperature at the inner areaof the laminate materials while allowing an injection moldingtemperature at the outer perimeter of the injection molding materials.

Referring now to FIG. 6, a side cutaway view depicts injection moldingtool 54 having an integrated activation device 60 positioned to activateadhesive between the laminate materials. Portions 56 and 58 of injectionmolding tool close relative to each other to align the laminatematerials without applying substantial pressure to the laminatematerials. Laminate pressure activation device 60 presses downward onthe laminate materials to provide a pressure associated with activationof adhesive 48 and heater 62 provides thermal energy to the laminatematerials that bring the adhesive to its activation temperature. As anexample, heater 62 may be suspended using a rubber pack available withinjection molding tools, a spring plate, a reverse injection plate orhydraulic activation. Heater 62 is, for example, a cartridge heatercombined with a beryllium copper heat plate that provides an adhesiveactivation temperature of greater that the approximately 140 degrees F.used during injection molding. In one embodiment, a ceramic insulatorhelps to isolate heater 62 from the primary surfaces of injectionmolding tool 54. After activation of the adhesive, laminate pressureactivation device 60 withdraws into upper injection molding tool 56, andupper and lower portions of injection molding tool 54 press together toprovide pressure associated with the injection molding process. Onceportions 56 and 58 of injection molding tool 54 define the area forinsertion of injection molding material as depicted by FIG. 7, injectionmolding material is insertion injection molded to encapsulate theperimeter of the laminated materials and then the tool opens to releasethe completed housing portion. Thus, one closing iteration of injectionmolding tool 54 supports both activation of adhesive to laminatematerials and injection molding of material around the perimeter of thelaminated materials and as features attached to the laminated materials.In alternative embodiments, alternative adhesive activation devices maybe integrated within an injection molding tool, such as ultraviolet,humidity, two part adhesive and pressure activation

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

What is claimed is:
 1. A method for manufacture of an informationhandling system housing from plural materials including an innermaterial of magnesium disposed at an interior of the housing and havingan inner thickness, an outer material of stainless steel disposed at anexterior of the housing and having an outer thickness, and anintermediate material of a filler disposed between the inner and outermaterials and having an intermediate thickness and an outer perimeter,the method comprising: aligning the plural materials to overlap in theform of the housing, the materials formed as separate layers movablerelative to each other; forming a lip in the outer material along atleast a portion of the filler outer perimeter; and injection molding atleast of portion of a perimeter of the plural materials to capture theoverlap of the plural materials in injection molding material, includinginjection molding of the lip to embed the outer material below theinjection molding material and proximate the inner material.
 2. Themethod of claim 1 wherein the outer thickness comprises 0.1 mm and theinner thickness comprises 0.5 mm.
 3. A method for manufacture of aninformation handling system housing from plural materials, the pluralmaterials including an inner material disposed at an interior of thehousing, an outer material disposed at an exterior of the housing and anintermediate material disposed between the inner and outer materials,the method comprising: aligning plural materials to overlap in the formof the housing, the materials formed as separate layers movable relativeto each other; forming openings in the inner material to expose theintermediate material at the interior of the housing; injection moldingat least of portion of a perimeter of the plural materials to capturethe overlap of the plural materials in injection molding material; andinjection molding structural features on the interior of the housing bybonding the injection molding material to the exposed intermediatematerial.
 4. The method of claim 3 wherein the structural featurecomprises a rib operable to aid in containment of a component in thehousing.